Valve released a new teaser trailer for "The Sacrifice" for both Left 4 Dead and Left 4 Dead 2, which should be available for the Mac sometime next week. Both will be seperate downloadable content, with Left 4 Dead 2 receiving an extra "No Mercy" campaign from its predecessor. Read on for a look at the trailer.

Calling all Team Fortress 2 players! And we know there's plenty of you out there because you've managed to kick our butts--repeatedly--in Frag the Editor Friday quite a few times now. Valve has released a new online store, caleed Mann-conomy, that will allow players to buy, trade and customize a ton of inventory items in the game's history, using their Steam Wallets. The Steam Wallets will be accounts that players can add money to--sort of like a gift card.

This morning, Valve announced a new add-on for its immersive, co-op zombie killing game, Left 4 Dead. "The Sacrifice" is due for release on October 5 and will continue to chronicle the struggle between the remaining Left 4 Dead survivors as they make their way to the South. "The Sacrifice" will also introduce a new style of finale gameplay called "Sacrificial Gameplay", where the players can device who will give their life so that other may live.

We love Valve, and we love them even more now that their games are available for us Mac users. But do you know who loves Valve even more than we do? Our sister magazine and cubicle neighbors, PC Gamer. This week, the crew is publishing up six different interviews they've had with the Valve team, with the first discussion in their series detailing the game publisher's strategies for the future, as well as why they've given us hats for our beloved Team Fortress 2 characters (this editor usually plays Pyro).

It looks as though Apple users, a typically intelligent, tech-savvy and genteel lot (yes, we're stroking our own egos here,) can add another particular to their growing list of resume foibles: 31337 6@/\/\3®. That's 'elite gamer' for all of you out there that don't hablas l33t speak. According to a monthly survey conducted by the game mongers at Steam, a growing number of the individuals enjoying their services are doing so on Apple hardware.

Mac gamers, are you stuck cycling through the same four games living on your hard drive? Well, fortunately there's a big game sale going on at Macgamestore.com and the Steam store, so it's the is perfect time to try out a few new games and reignite your love for gaming on your Mac machine.

Today's Wednesday and you know what that means: it's time for Valve to release another one of their popular game titles for the Mac platform. Today, Valve is launching Counter-Strike: Source and Mac users can now engage in this dashing, daring and downright tricky multiplayer shootout. The Mac version allows cross-platform play--much like Team Fortress 2--and this particular update also makes achievements, stats and engine updates available to Macs users via Steam.

Valve will be offering a 66% discount on Counter-Strike: Source. So what're you waiting for? Go and get it, and we'll see you for Frag the Editor Fridays.

While Steam on the Mac has only been out for a few weeks, many on the Mac|Life staff have fallen in love with the Valve game, Portal. Yesterday we got a glimpse at the Portal teaser trailer and today we have gameplay footage from E3.